Effects of cultivar and culture conditions on γ-aminobutyric acid accumulation in germinated fava beans (Vicia faba L.)

BACKGROUND: High levels of gamma-aminobutyric acid (GABA) accumulate in plant tissues undervarious stresses. GABA accumulation isalso influenced by cultivar. This aim of this study was to select the most promising cultivarof fava bean for GABA accumulation and to optimise the culture conditions for GABA production in germinated fava beans by response surface methodology based on central composite design (CCD). RESULTS: GABA content and glutamate decarboxylase activity in germinated seeds of cultivar S2 were significantly higher than those in other cultivars (P < 0.05). A significant negative correlation (r = -0.765, P < 0.05) between germination percentage and 1000-kernel weight was observed. There was a linear relationship between GABA content and sprout length (R-2 = 0.816). The regression model fitted to the experimental data of CCD was valid in predicting GABA production in germinated fava beans. Temperature and pH value of the culture solution had significant effects on GABA content in germinated fava beans. Under optimal culture conditions (33.6 degrees C, pH 3.19 and an air flow rate of 1.19 L min(-1)), GABA content reached up to 2.41g kg(-1) dry weight, about 48 times that in raw seeds. CONCLUSION: Germinated fava bean is a good resource of GABA-rich food. Both cultivar and culture conditions have significant effects on GABA production. (c) 2009 Society of Chemical Industry